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All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Opportunities and Challenges for Remote Microreactor Operations

The nuclear industry is developing new advanced reactor technologies, and many companies are embracing this advancement by pursuing the development of microreactors. The term microreactor generally refers to a nuclear reactor with an operating power of 20 MW or less. The power range of microreactors makes them appealing for many use cases, such as powering remote communities, mining sites, and military bases. Most of the microreactor designs being pursued will incorporate remote facility operations into the final product. However, no framework has yet been developed to determine what remote operations systems require for reliable, resilient, and secure operation of a microreactor. This work identifies the challenges unique to remote operations and monitoring for microreactors specifically regarding instrumentation and control, communication methods, regulatory requirements, and operational policies. The types of commands and sensor measurements that must be transmitted between the facilities as well as methods for verifying the trustworthiness of these signals are assessed. This work evaluates the security, reliability, and performance requirements that must be met when considering the selection of communication hardware and protocols for use in remote operations. Also, an assessment was performed to study how remote operations fit within current regulatory requirements and what may need to be updated in regulatory policy to allow for remote operation. Finally, the operational contingencies unique to remote operations that must be in place for response to abnormal events are identified. This paper details these challenges and research opportunities to provide a foundation for the design of remote operation systems.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2017

Challenges and Lessons Learned Performing Subsurface Investigations at a Radiologically Contaminated Site in an Urban Area - 17391

At the Formerly Utilized Sites Remedial Action Program (FUSRAP) Maywood Superfund Site (FMSS) the U.S. Army Corps of Engineers (USACE) has performed minimally intrusive (i.e. non-excavation) sub-surface investigations in soils, underneath roadways, and within buildings to generate information needed to determine whether contaminated material was present and to delineate the nature and extent. Given that thorium-232 (Th-232) contaminated material is present below various surfaces and that the current iteration of the Multi-Agency Radiation survey and Site Investigation Manual (MARSSIM) has only marginal guidance on evaluating and releasing subsurface data, survey design and implementation required detailed up front planning and post investigation analysis and reporting. This paper will discuss the approaches USACE utilized during a recent roadway investigation, some of the challenges encountered, a discussion of techniques used and results obtained, and an overall summary of pitfalls identified and lessons learned for future efforts. In order to evaluate selected areas, direct push technology was utilized in conjunction with plastic tubing to facilitate core capture and sample collection. PVC piping was inserted in each bore hole to prevent borehole collapse and facilitate downhole gamma logging. Soil samples were collected from the surface, from native material or the bottom of the boring, and from the interval or intervals which exhibited elevated downhole gamma readings, and from areas with an identifiable marker of contamination (i.e. soil discoloration) at the judgement of the field staff. Data was collected and evaluated using the approaches laid out in MARSSIM as best possible. As MARSSIM was developed to only address surface contamination, USACE, in agreement with regulators and stakeholders, utilized a 'varying plane' approach, where samples are evaluated as if on a single plane, and only the highest concentration encountered at any point is considered. Because the areas investigated were not easily cast into simple geometric shapes adhering to MARSSIM design criteria, it was important to ensure that Survey Unit design for Class 1 Survey Units were reasonable. All Class 1 SUs were contiguous survey units. Class 2 survey units were allowed to be non-contiguous provided that they are situated in close proximity to one another and share the same geology, conceptual site model, history, and radionuclide concentrations. The information contained in this paper will benefit Projects working with subsurface contamination which may require subsurface investigation and an understanding of the logistical, technological, and regulatory challenges. The ultimate outcome of this effort was the successful delineation of areas of contamination which will facilitate current utility work and guide future remediation. (authors)

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DOE OSTI2023

CHALLENGES IN THE DEVELOPMENT OF THE ELECTROREFINING PROCESS AT Y-12

In order to ensure future capabilities of the Y-12 site as older buildings retire, a new process was developed, the Metal Purification Process. The purpose of this new process is to provide a simpler and more efficient uranium metal purification that the previous multi-staged, complex chemical processes. The basis for this technology currently exists in the US DOE complex, but it has not been utilized on a large scale for uranium at higher enrichments. The system requires larger-geometry vessels and furnaces in order to meet the through-put requirements. The crux of the process is the electrorefining cell, consisting of several concentric liners and an unfavorable geometry cylindrical crucible. Within the crucible, a molten Li-CL-KCL-UCL3 salt electrolyte is present. ‘Dirty’ metal is placed into a loading basket and loaded into an electrorefining cell. Here, the metal reacts into the molten salt within the cell to form UCL3, while ‘clean’ metal simultaneously plates out from the salt electrolyte in the form of metal dendrites. These dendrites are then collected and removed from the cell. After removal from the cell, the dendrites are taken to a furnace to remove adhered salts. Then, the salt-free dendrites are moved to a separate furnace for consolidation into the final product form. The development of the Criticality Safety Evaluation for this complex system brought with it many NCS Challenges and lessons learned. These challenges include: design decisions for ensuring subcriticalty in the electrorefining cell during abnormal conditions, the interface of the main glovebox system with auxiliary systems such as the purification system and designated storage, implementation of mass tracking, and concerns from production and operation regarding the movement of material within the system.

36 MATERIALS SCIENCE↗
DOE OSTI2019

96 Park Way Vicinity Property Remediation Challenges at the FUSRAP Maywood Superfund Site, Maywood, New Jersey - 19216

The Formerly Utilized Sites Remedial Action Program (FUSRAP) Maywood Superfund Site (FMSS), 'the Project,' was transferred to the US Army Corps of Engineers (USACE) in 1997. Shortly thereafter, USACE initiated FUSRAP remediation efforts on 24 commercial and residential properties and, in addition, the Project team evaluated properties previously addressed at the FMSS. One of those properties was located at 96 Park Way in Rochelle Park, New Jersey. The property history included removal of contaminated soil in 1985 by the US Department of Energy (US DOE). Soil sampling performed after removal of contaminated soil indicated the cleanup met applicable guidelines in place at the time. A Five-Year Review of the FMSS conducted by the US Environmental Protection Agency (USEPA) in 2009 found that 96 Park Way did not meet the current residential cleanup levels for the site and recommended additional study and remediation, if warranted. The current levels are established in the approved cleanup plan for the FMSS (known as the Record of Decision [ROD]) issued in 2003. Based on USEPA's recommendation, USACE carefully reviewed all available records for the property. The review considered the differences between the soil cleanup standards used in the 1980's and the 2003 ROD standards, which are slightly more restrictive for deeper soils. The USACE conducted detailed field studies at 96 Park Way in 2014-15 to address the USEPA findings. This work included gamma walkover surveys and soil sampling to depths of approximately 3.5 meters. The results identified three discrete areas at depth that did not meet the ROD residential soil cleanup standard: two areas bordering an adjacent highway (New Jersey Route 17) and one along railroad property adjacent to the site. To address these areas, soil removal actions were conducted in 2016-17. The principal challenge with construction, engineering, and community relations was the property housed two sensitive facilities: a long-term assisted care living facility and a short-term post-surgery rehabilitation center. The operations at these facilities could not be interrupted in any way during FUSRAP activities. The three FUSRAP-impacted areas were addressed and restored in coordination with the USEPA, property management, and local officials. Site restoration presented a particular challenge well after the remedial action was completed, as the property owner and the government disagreed on the level of restoration. Those negotiations are ongoing as of this writing. (authors)

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DOE OSTI2019

The Challenges of Repository Operation in an Existing Mine - 19339

A generally accepted principle related to long term management of radioactive waste/ spent fuel is the isolation in a geological repository. In Germany, the disposal operation of low-level waste (LLW) and intermediate-level waste (ILW) started in the Asse II mine in 1967 and in the former German Democratic Republic in the Morsleben repository in 1971. After the German reunification, the responsibility for the existing sites changed several times until the Bundesgesellschaft fuer Endlagerung (BGE) became new license holder for both sites in 2017. The BGE is responsible to carry out the operative tasks of searching for a high-level waste (HLW) repository, the planning and construction of the Konrad repository for the emplacement of low- and intermediate-level waste (LILW), the operation of the Asse II mine including the retrieval of the emplaced waste, and the preparation for the closure of the Morsleben repository. Nevertheless, the challenges of repository operation in an existing mine have not changed in all these years, as the regulatory framework is mainly written for Nuclear Power Plants (NPPs) and is difficult to adapt for a repository mine. In particular, conditions in a mine are substantially different from 'clean' above-ground nuclear installations. Dust due to mining activities, relatively high temperatures, and a corrosive atmosphere in a salt mine might be present. Therefore, the usability of the repository for several decades during the different operational phases, i.e. planning, construction, emplacement, and closure, can only be ensured by continuous maintenance. Furthermore, the atomic law is applicable for above-ground facilities and the mining law for mines of every description. The difficulty of geological repositories is to ensure that both laws are going to be applied above and below ground with no regulatory framework tailored especially for such sites. A special case is the Asse II mine where the mining law was applied from the very beginning, before the atomic law needed to be established later on and now requires the retrieval of the radioactive waste before decommissioning. In this presentation, similarities and differences in the legal framework of the repositories in the responsibility of BGE and some operational experiences throughout the years are described. This applies to the radiation protection regime, the excavation ratio, the host rock stability and the backfilling concepts of the mining areas. Further challenges arise from the demonstration of long term safety according to the state-of-the-art of science and technology for either existing repositories/ mines or those under construction or planned. (authors)

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DOE OSTI2019

Panel Session 51: Idaho Transuranic Waste Challenges, Solutions and Implications for the Future (3/5)

This panel focused on the retrieval, characterization, treatment, certification, and shipping of transuranic (TRU) waste at the Idaho National Laboratory (INL) Site, Idaho, USA. The INL began receiving TRU waste from offsite generators (primarily the Rocky Flats Plant in Colorado, USA) beginning in 1954. Until 1970, the INL Site disposed of barrels, boxes, and other debris in a shallow, unlined landfill. Beginning in 1970, the INL Site began storing TRU waste on an asphalt pad, which was then covered with several feet of soil. This practice continued until the late 1980's at which time a large air support building was erected over the waste. In the mid-to-late 1990's, the air support building was removed and a massive building was constructed over the entire dirt mound. Contractors retrieved the waste from the early 2000's through February 2017 to support an Idaho Settlement Agreement milestone that required the retrieval of 65,000 cubic meters of TRU waste and removal from Idaho. This panel focused on the Idaho Transuranic Waste Challenges, Solutions and Implications for the Future. The Idaho Transuranic Waste Program includes buried and stored waste retrieval and processing of contact- and remote-handled transuranic waste. Over the duration of the program, the Idaho site has conducted targeted retrieval of buried waste from the 1950's and 1960's; designed, permitted, built, operated, and completed the mission of a facility to process 65,000 cubic meters of waste; and shipped more than 57,000 cubic meters of waste to WIPP. Presentation proposed: Transuranic Waste Challenges and Solutions (Hoss Brown, Fluor Idaho, LLC (USA), John McCoy, Fluor Idaho, LLC (USA), James Malmo, US DOE (USA), Doug Pruitt, Department of Energy Idaho Field Office (USA), Kenneth Princen, US DOE (USA))

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DOE OSTI2019

Panel Session 61: Challenges in the US DOE HLW Tank Management Program

Approximately 50 people attended this panel session which focused on the successes and challenges in DOE high-level radioactive tank waste management with special emphasis on tank waste processing and waste disposition. Panelists discussed approaches, results, and lessons learned in addressing challenges in construction, start-up, and processing of tank waste and its ultimate disposition that is critical to tank waste management at Hanford, Savannah River, and Idaho sites. Presentations proposed include: 1 - Liquid Waste Program at the Savannah River Site (James Folk, US DOE (USA)); 2 - Progress on Hanford's Tank Waste Treatment Mission (Tom Fletcher, US DOE (USA)); 3 - Idaho Tank Waste Program (Joel Case, US DOE (USA))

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Panel Session 110: Collaboration Across Borders to Deliver Cleanup and Decommissioning Challenges

This panel session engaged panelists from multiple countries on the issues with the implementation of in situ decommissioning/disposal and how to communicate more effectively with stakeholders. Presentations proposed include: 1 - Collaboration Across Borders to Deliver Cleanup and Decommissioning Challenges (Laurie Judd, Longenecker and Associates (USA)); 2 - Collaboration Across Borders to Deliver Cleanup and Decommissioning Challenges (Kavita Murthy, Canadian Nuclear Safety Commission (Canada))

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Challenges of Maintaining Institutional Controls: Maintenance of an Alternate Water Supply- A Case Study - 19583

The US Department of Energy (DOE) cofunded an alternate water-supply system (AWSS) with the Indian Health Service that was installed in the vicinity of the former uranium mill site near Riverton, Wyoming, as one of the institutional controls (ICs) at the site. The AWSS was constructed in 1998 to supply drinking water to residents within the IC boundary in lieu of drinking untreated groundwater that could potentially be impacted by the contaminated shallow aquifer. The AWSS derives water from three source wells that pump groundwater from the sandstones of the Wind River Formation to a 3.8 x 106 liter (1,000,000 gallon) storage tank. Water from the storage tank is distributed throughout the AWSS service area by approximately 18 kilometers (11 miles) of PVC pipeline. The AWSS currently serves 103 residential customers and 1 commercial customer. DOE and the Northern Arapaho tribe (owner of the AWSS) have partnered over the years to address numerous challenges with the AWSS that included engineering assessments, scientific investigations, sampling support, a hydrant flushing program, and funding. Challenges with the AWSS have included the following: (1) Transmission pipe installed during initial construction did not have a pressure rating high enough to account for system pressure surges. (2) AWSS appurtenances were initially installed without accounting for the effects of corrosive soils on metal components. (3) Natural radium from the Wind River Formation groundwater builds up in the AWSS transmission pipes to levels above the primary drinking water standard because of the lack of a flushing program, dead-end lines, and low system demand. A 2-year study showed that a unidirectional hydrant-flushing program will control the radium buildup. (4) Aging system components including hydrants, valves, and pumps are nearing their effective lifespan and are in need of replacement. (5) With the addition of large commercial customers, demand on the system has increased since the initial installation of the system, and future growth in the area will continue to increase demand. (6) Additional connections and integration of the AWSS with an areawide water system in the near future will require changes to the current flushing plan and add additional complexity regarding areas of responsibility. (7) A well-organized financial and administrative infrastructure is not in place, and additional revenue is needed to operate, maintain, and improve the AWSS. To be a viable IC, the AWSS will require management, maintenance, and upgrades to provide safe drinking water until groundwater meets drinking water standards. Responsibilities and funding for maintaining the AWSS as a viable IC are the focus of current discussions, and decisions regarding responsibilities and funding will be formalized in future cooperative agreements and memoranda of understanding with the owners. (authors)

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DOE OSTI2020

Panel Session 115: Collaboration Across Borders to Deliver Cleanup and Decommissioning Challenges

This panel focused on where multiple countries have collaborated to solve difficult remediation and cleanup challenges through either formal or informal means. The focus was to share real examples of where collaboration has accelerated cleanup saving time and money. This could be through policy or process improvements, technology transfer or sharing R and D, or other means of collaborative efforts. Panelists with presentations: Canada-AECL Collaboration Across Borders (Richard Sexton, Alastair MacDonald); Collaboration Across Borders to Deliver Cleanup and Decommissioning Challenges (Anthony Banford); IAEA Perspective on International Collaboration in D and ER (Horst Monken Fernandes); How, Why and Benefits of Collaboration (Kurt Gerdes)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Challenges and Solutions in Operation and Lay-Up of the Modular Caustic- Side Solvent Extraction Unit - 20078

The Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) was designed and constructed to provide interim salt waste processing so that the Liquid Waste Disposition Program (LWDP) could continue waste removal and tank closure until start-up of the Salt Waste Processing Facility (SWPF). MCU processes Clarified Salt Solution (CSS), or salt solution (SS) that has undergone actinide removal/filtration, to produce two waste streams: the cesium laden Strip Effluent (SE), which is incorporated into glass at the Defense Waste Processing Facility (DWPF), and the cesium depleted Decontaminated SS (DSS), which is incorporated into grout at the Saltstone Production Facility (SPF). MCU completed start-up in 2008 with an initial operating life of 3 years and design life of 5 years. Prior to reaching the end of the design life, multiple critical components were upgraded and/or replaced to mitigate risks associated with any delays in SWPF start-up. During the remainder of operation (until June 2019), MCU was challenged to maximize processing with minimal additional modifications to repair/improve aging infrastructure, while maintaining low levels of risk to workers and the environment. Notable challenges during the extended operating life of the facility involved both mechanical and operational issues. Two of the most significant issues were the increased frequency of Process Vessel Ventilation (PVV) High Efficiency Particulate Air (HEPA) filter change-outs and the biofouling of the SE coalescer (SEC). The major impacts of both issues were that replacement of these components 1) resulted in high exposure to workers, and 2) required substantial downtime, thus hindering achievement of processing goals. PVV HEPA filter replacements are required based on dose rate and differential pressure (dP) limits. After introducing a higher-curie feed to MCU, the operating time between change outs was reduced by approximately half. SEC replacements are required based on dP limits. After restarting from an extended outage, the operating life of the SEC was significantly reduced by more than half due to biofouling. As a result of extensive troubleshooting and process improvements, the facility was able to recover performance and extend the operating life of the PVV HEPA filters and the SEC media. Through troubleshooting both of these issues, the facility was also able to learn from prior experience and adapt in order to minimize down time and maintain throughput. Although the facility took advantage of short periods of downtime to perform nonintrusive troubleshooting and minor corrective/preventative maintenance activities, longer outages were periodically required for corrective maintenance involving process cell entry. During these outages, remote tools and specialized shield plates were employed to minimize dose to workers. Mock-ups of non-routine maintenance activities were critical to early identification of potential issues and improvements, which shortened outage duration. Consistent with the facility's operational strategy, evolutions needed for MCU layup were identified and sequenced to ensure safe conditions within the facility, meet pre-defined criteria for lay-up configuration, and protect workers, while minimizing the impact to SWPF integration. De-inventory and flushing of process areas was prioritized so that the total residual inventory was reduced as efficiently as possible. This paper discusses lessons learned and best practices from troubleshooting unique issues, performing complex maintenance activities, and implementing a layup strategy that best supports the overall system mission. (authors)

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DOE OSTI2020

USACE FUSRAP Records Management Challenges in the Digital Age - 20242

In late 2016, the U.S. Army Corps of Engineers (USACE) implemented a Headquarters-supported nationwide records management initiative managed by the USACE-New England District to address the digitization and organization of Formerly Utilized Sites Remedial Action Program (FUSRAP) project files. This initiative will prepare USACE FUSRAP for moving toward a fully electronic system of records management. Additionally, the records management initiative streamlines the process and prepares the Administrative Record (AR) and Permanent Record (PR) file for transfer from USACE to the U.S. Department of Energy (DOE)-Office of Legacy Management (LM) following project closeout. Over the past couple of years, USACE and DOE-LM have been working to finalize a joint guidance document to assist in the FUSRAP records transition process. However, there remain key records management topics that require further discussion and development. Specifically, these topics include the implementation, process, and procedure for the capture of social media records and compliance with Section 508 of the Rehabilitation Act of 1973 (29 USC 794d), as amended. Due to advances in technology and the ease of communication it provides, USACE is using social media more often to interface with the public than 5, 10 or 15 years ago. The identification and capture of these records are challenging because it requires each USACE district or producer of a record to track what has been released through social media so that it can be captured as part of the AR or PR. USACE is currently evaluating processes and procedures for social media records capture. This paper explores how social media is being used by USACE across FUSRAP projects and best practices for the capture of social media records. Public accessibility to the project AR is required under the Comprehensive Environmental Response, Compensation, and Liability Act, which USACE FUSRAP must follow. As USACE FUSRAP ARs are converted to a digital format, greater accessibility to the files can be provided through web sites or other electronic media. However, Section 508 of the Rehabilitation Act must be considered when releasing electronic files to the public. Under Section 508, government agencies must ensure that information is made available to the public in a format that provides equal access to persons with disabilities. This paper discusses the electronic records requirements under Section 508 and addresses broad implementation of compliance across large digital records sets. Records management challenges are presented in the context of the FUSRAP records management program; however, these records management considerations and best practices are applicable across all Federal agency records management programs. Examples presented will further aid in understanding electronic records requirements that may be included on new USACE FUSRAP contracts as well as upcoming National Archives Records Administration requirements that will move us toward an electronic government. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Challenges and Practical Solutions for Conducting Structural MARSSIM Surveys in Elevated Radon Environments - 20413

The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) [1] provides comprehensive guidance for the development and implementation of radiological surveys conducted to demonstrate compliance with a dose- or risk-based cleanup goal during final status survey. The MARSSIM methodology follows an integrated strategy combining direct measurements and sampling to assess uniform residual contamination, and scanning surveys to identify localized areas of elevated activity. Building surveys assessing residual surface contamination present unique challenges from reliance on field measurements that may be subject to less than ideal environmental conditions. Additionally, limited characterization and excessive conservatism incorporated into the conceptual site model may result in derived concentration guideline levels (DCGL) and, as a consequence of relatively inefficient field instrumentation, corresponding attributable count rates generally comparable to background. The presence of elevated ambient radon concentrations and associated progeny deposition both exacerbate these intrinsic survey challenges and introduce a series of technical, logistic, and administrative obstacles that can wreak havoc on the statistical legitimacy of each component of the MARSSIM process. Short-lived radon progeny including polonium-218, lead-214, bismuth-214, and polonium-214 produce excessive alpha and beta radiation that may decrease instrument sensitivity through an increase in background count rates, and, at worst, may result in incorrect survey unit failure through the simulation of residual surface activity. Aside from the obvious solution of exhaustive radon mitigation, the primary objectives are to distinguish between radon progeny deposition and actual surface activity, and collect sufficient defensible data. The following is a technical discussion of the consequences of performing building MARSSIM surveys in the presence of elevated ambient radon atmospheres, conceptual examples, and an overview of practical strategies to minimize the effects of radon interference while collecting sufficient defensible data to complete the survey. (authors)

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DOE OSTI2020

The Challenges of Air Monitoring at a Soil Remediation Project in a Suburban Setting - 20448

Air monitoring during soil excavation at a chemically and radiologically impacted site in a suburban setting presents unique challenges. Site activities were conducted in a manner that minimized the release of airborne particulates of concern, principally radionuclides of concern (ROC). Dust and air monitoring were performed to ensure the public was not being exposed to the soil contaminants. The project team collected representative air and dust data while being mindful to not impose on the lives of residents in the area. Due to the close proximity to the public, there was a high level of oversight from the client and regulatory agencies. The challenges involved with air sampling at this soil remediation site located in a suburban setting included the number of contaminants, the ranges of risks and hazards presented by the contaminants and the method of remediation, the concerns of the regulators and the public, and the perception of risk from the public. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Panel Session 145: Challenges and Opportunities in Establishing a System for Transportation of SNF/UNF

Issues associated with establishing a SNF Transportation System in the U.S. are complex. In part, this is because in the US when discussing SNF, there are two distinct categories. The two categories represent significant differences in ownership, transportation-regulator, and even the physical characteristics of the SNF. Specifically, the physical differences in the SNF include size of the rods, associated quantities to be shipped, cladding material, and radionuclide content/enrichment. The first is commercial SNF (i.e., that associated with nuclear power plants), owned by utilities, until a permanent repository is built with DOE obligated by law to then assume the responsibility for shipping and ownership of the SNF. Since no-permanent repository currently exists, most commercial SNF is stored near the reactor in which it was installed, hence requiring no shipments. Although current shipments of commercial SNF are very limited, the few that do occur are generally performed to support a utilities SNF consolidation effort utility and for post irradiation examination/testing. However, with approximately 83,000 metric tons currently being stored at more than 70 sites around the U.S., when a permanent repository becomes available, the required number of shipments will be extensive. The second category is DOE and research reactor fuel. These fuel rods are generally much smaller in length than commercial fuel rods, with the quantity of rods transported in a shipment significantly less than the number of rods in a typical commercial fuel assembly. Currently, most of the SNF shipments within the U.S come from this category. DOE is currently managing about 2500 metric tons of heavy metal of SNF. This panel focused on updates and status of transportation of SNF/UNF. Panelists provided updates and information on continuing impacts, risk assessment, equipment (rail cars, handling, securement), possible rail routing, and proposed inspection equipment/routing prior to shipments. Panelists with presentations: Preparing for Nuclear Waste Transportation (Daniel Ogg); Challenges and Opportunities in Establishing a System for Transportation of SNF/UNF (Kathy Langan); UNF Transportation: Challenges and Opportunities (Michael Valenzano)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Getting to 100%: Six Strategies for the Challenging Last 10%

This presentation summarizes the challenge of decarbonizing the last 10%" of the power system and discusses six strategies for addressing that challenge. This presentation was given at the IRA, BIL, and the Future of Energy: A Summit to Support State Implementation" workshop in Washington, D.C., in April 2024.

carbon capture↗
DOE OSTI2024

Solving the Grid Optimization Competition Challenge 3 Problem

The Grid Optimization Competition Challenge 3 Problem posed a multiperiod security-constrained unit commitment problem with base-case AC power flow. The problem formulation includes binary unit commitment decisions, nonlinear AC power flow and balance, dispatchable loads, and linearized contingency real power flow, among other features. This talk will present a modified consensus ADMM algorithm, which splits the problem into mixed-integer linear and nonlinear components, as a heuristic solution method for this large-scale mixed integer nonlinear program. We will present some computational results from the competition for our implementation and reflect on the challenges of participating the grid optimization competition.

AC power flow↗
DOE OSTI2024

Practical challenges of model predictive control (MPC) for grid interactive small and medium commercial buildings

To the urgent call for mitigating climate change, substantial initiatives have been undertaken to deploy grid-interactive heating, ventilation, and air-conditioning (HVAC) controls, such as model predictive control (MPC) for buildings. These efforts typically aim to curtail peak energy demand, shift load and enhance overall energy efficiency. With the recent development of low-cost MPC technologies that don’t require extensive instrumentation or manual modeling, small and medium commercial buildings (SMCBs), which rarely utilize advanced HVAC control systems, have become candidates for grid-interactive efficient buildings (GEBs). However, despite the potential benefits and maturity of the technology itself, several practical challenges remain in real-world implementation. In this paper, we share the practical challenges that we have encountered in implementing and testing three types of MPC solutions (ON/OFF unit, dualfuel, and VRF systems) on multiple SMCB sites. We describe the MPC deployment process and discuss the lessons learned. The site selection, eligibility, and retrofit availability (e.g., utility price structure, thermostat communications, etc.) are the main discussion points at the beginning of the project. Also, the modeling automation and the best practices for interacting with endusers and handling erroneous situations are presented for successful operations.

woo Ham, Sang↗